Vibration reducing device



1938. R. R. R. SARAZIN 2,127,888

VIBRATION REDUCING DEVICE Filed Nov. 21, 1935 m m m M k h W V fi M Kw Z -1 N. m.

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Patented Aug. 23,

UNITED STATES PATENT osmosaizuas VIBRATION REDUCING DEVICE Raoul Roland Raymond Baralin, st-m'rr nee Application November 21, 1935, Serial No. 50,992

In Germany December 11,1934 1 1 Claim. (Cl. 74574) The present invention relates to vibration rehereinafter referred to in the following detailed ducing devices of the kind including at least one description.

movable mass connected to the vibrating part The examples of the invention hereinafter dein such manner as to be able to oscillate with scribed refer to the case of a device for reducing respect thereto. The invention is more especially, the vibrations of the shaft I of a multi-cylinder I although not exclusively concerned, with devices engine. 5 of this kind in which the movable masses are This device includes a plurality of masses 2, suspended on the vibrating part in a manner each connected to shaft I through at least one analogous to the arrangement of bifllar pendurolling body 3 adapted to roll. on the one hand, 0 lums. along a runway connected to the shaft, and, on

The object of the present invention is to prothe other hand, along a runway connected to vide a device of this kind which is better adapted the mass. to meet the requirements of actual practice than According to the invention, the runway carried devices of the same kind used up to this time. by one of the elements to be connected together According to the essential feature of the presis a runway 4 extending from one side to the 15 cut inventiomthe two elements above referred to, other of said element. to wit, the vibrating part and the movable mass, On the other hand, the other element includes are connected together by means of a rolling two parts forming lugs extending on either side body cooperating with runways carried by these of said runway respectively, each of said lugs two elements, the runway carried by one element carrying a runway 5 or 6 overlapping the. first 20 extending from one face to the other face therementioned runway. of, while the other element includes two lugs or Finally, a rolling body or structure 3 extends similar parts provided on either side of said through the overlapping parts of the spaces limflrst mentioned element close to said faces thereited by these runways, so as to be able to cooper- 5 of respectively, runways overlapping the first ate with these three runways. mentioned runway being carried by said lugs The section of the portion of this rolling body respectively, whereby the rolling body or analothat cooperates with runway 4 may be either gous structure can extend on either side 01 the identical to thesections of the portions adapted first mentioned runway into the two other runto cooperate with runways 5 and 8 or different ways with acertain play. therefrom. With this arrangement, under the 30 According to another feature of the invention effect of the centrifugal force, this rolling body is this rolling structure includes at least two disheld and maintained in position between the tinct parts adapted to turn freely with respect un ay c d y n Of e e e ements and the to each other about a common axis, one of these runways carried by the other element.

5 parts being adapted to cooperate with the runway R w y 5 d 5 m y be iven any ui ble I carried by the vibrating part and the other with ut ne o t c t s Ou y be a D the runway carriedby the movable mass, tion Of 8. curve Of sllmclent length in order that Other features of the present invention will the mass may m ve wi h h desired amplitude result from the following detailed description oi w th r sp ct to t e v brati pa t to which it is some specific embodiments thereof. to be connected, such runways being, for instance 40 Preferred embodiments of the present invena ri d y p n sw v r s der that tion will be hereinafter described with reference it is more advantageous to give t e Out i es to the accompanying drawing, given merely by the shape of closed curves, the runways being, way of example, and in which: in this case, formed in holes provided in the ele- Fig. 1 shows, partly in elevation and partly ments to be connected together. 45 in cross section, a device for reducing vibrations Of course, the l n y must t i h a made according to a first embodiment of the intam-play n t s h les (sa a play of s me milvention; limeters in the case of a rolling body of a diameter Figs. 2, 3 and 4 are longitudinal sectional equal to 10 millimeters).

.30 viewsshowing three analogous devices made 9.0- Owing to the provision of this play, masses 2 cording to three other embodiments of the inshall oscillate when the rotary movement of shaft vention, respectively; I 'i is not regular and their movements shall de- Figs. 5 and 6 are diagrammatical views illuspend upon the shape of the runways and that of trating the principle of working of the device the rolling bodies cooperating therewith.

5 according to the invention .and which will be In the diagrammatical views of Figs. 5 and 6,

it has been assumed that the outline l of runway 4 is a circular cylindrical surface of a radius equal to n, that the outline 8 of runways 5 and 6 also is a cylindrical circular surface the radius 1': of which is equal to n, and finally that the rolling body 3 is a portion of a circular cylinder of the same diameter over its whole length and of a radius equal to n. The center of curvature M1 is rigidly connected to the mass and the center of curvature M2 is rigidly connected to the shaft. The contact between rolling body 3 and the outlines 1 and 8 of the runways takes place, for the position of rest, at points S1 and $2.

In order to determine the radius of the pendular movement of mass 2, it is necessary to follow, in the course of the oscillation, the movement of point M2.

While, in Fig. 5, the relative position of the outlines of the runways corresponds to the state of equilibrium, in Fig. 6, this relative position is shown in the case of a pendular deviation of mass 2. The latter rolls through the outline l of its runway and with the interposition of rolling body 3 on the outline 8 of the runway of the shaft. The rolling body 3 and the runways corresponding to outlines 'l and 8 are maintained in contact together at new points of contact S1 and S2. The points that were in contact together in the position of rest shown by Fig. 5 have moved away from one another and are now located atSr, S1 and S'2, S"2. The center of curvature M2 has moved along a circle 9 the center of which coincides with the center of curvature M1 corresponding to outline I, the radius of this circle 9 being n. Assuming that:

then the value of radius T4 is r4=2(r1-rs).

It follows that if radii r1, T2 and T3 are suitably chosen, it is possible to obtain a radius of curvature n as small as it is desired, if radii r1, 1'2 and 3 are given the value necessary for high centrifugal forces.

Although the specific arrangement of the device may vary widely, I consider that it is particularly advantageous to use an embodiment corresponding to one of the specific examples shown by Figs. 1 to 4.

In these embodiments, runways 5 and 6 are provided in two lugs carried either by a plate ID rigidly connected to shaft i (as in the examples of Figs. 1, 3 and 4) or by mass 2 (as in the case of Fig. 2). These two lugs are disposed at an interval from each other sufficient for fitting between them at least one part of the other element. For instance the runways consist of rings of tempered metal driven with a force fit into said lugs and into the element disposed between said lugs.

In the embodiment of Fig. l, the rolling bodies 3 are mere cylinders consisting of a single piece, for instance of steel, which are kept in position transversely through any suitable means, such as small end plates II. The two lugs are rigid with plate l and masses 2. are disposed between these lugs.

On the contrary, in the embodiment of Fig. 2, plate I0 is fixed to the crank pin of a crankshaft and masses 2 are recessed so as to fit on either side of said plate. The rolling bodies are made as in the embodiment of Fig. 1.

In the embodiment of Fig. 3, the rolling bodies consist of two different parts which can turn freely with respect to each other about a common axis, one of these parts being adapted to roll on runway I and the other one on runway 5, 6. Each of these rolling bodies includes a central part l2 adapted to run along runway 4. This central portion is provided, on either side thereof, with coaxial trunnions on which two rollers l4 adapted to roll on runways 5, 8 are mounted freely. Preferably, bushings l3 are interposed between these trunnions and these rollers. Any lateral displacement of the composite rolling body thus formed is prevented for instance by small plates which screw from the outside on the lugs of plate I!) and which are provided with stops l6 of tempered metal so as to avoid wear and tear.

In order to ensure the lubrication of this mechanism, 011 under pressure is fed through a conduit I! provided in shaft l and then through a conduit I1 communicating with the preceding one and advantageously provided inside the very mass of the bolt l9 through which the vibration damper is secured to shaft I, a conduit l8 conveying the lubricant to the runways themselves.

This arrangement prevents any wedging as might take place when the rolling bodies are made of a single part due to friction under the action of very high centrifugal stresses,

Such wedging may occur under the following circumstances: Although the runways occupy a position such as that shown by Fig. 5, the rollers may be located in unsymmetrical position. If the rolling bodies are made of a single part, they are then wedged in the space common to both runways and, in view of the frictional stresses that are developed, said rolling bodies cannot be disengaged and come back into symmetrical position. The provision of rolling bodies made of several parts rotatable with respect to one another fully avoids this drawback since one of these parts can roll on the runway corresponding to the mass independently of the rolling movement of the other part with reference to the runway of the plate.

In the embodiment of Fig. 4, the rolling bodies are not made of several distinct parts movable with respect to one another. But they are provided with toothed rings and 2|, in such manner that the rolling bodies cannot slide with respect to the runways. The toothed rings 20, as well as toothed ring 2i are fixed on a central rod by means of a key 22 which prevents them from turning with respect to said rod. Furthermore they are so devised as to prevent any axial displacement. The internal gear 23 which coacts with toothed ring 2! is keyed with respect to mass 2 by means of a key 24, while the internal gears 25 which coact with toothed ring 20 are maintained by'means of keys 26 so as to prevent them from rotating with respect to plate Ill. The pitch circles of the internal gears have the same respective diameters as the runways to which they correspond.

The rolling bodies may also have a shape different from that of the cylinders shown in the drawing. They may consist, for instance, of any type of cylinder or of any other shape, the generatrix of which is a curve.

In a similar manner, the shape of the runways is not necessarily that of a cylinder. It may also be of any other kind. Some shapes have the advantage that the center of the oscillation of the masses that damp the vibrations may be displaced in a predetermined way during the oscillation and that the pendular curve may be given any desired curvature. This advantage may also be obtained when the cylindrical runways have diii'erent radii of curvature, respectively.

Oi course, the rolling bodies may consist of members which are of any suitable shape.

In all cases, in order to prevent undesirable movements of the masses duringthe periods of starting or of stopping of the machine on which the vibration reducing device is fitted, I may provide suitable stops such as screws 21 adapted to bear, through their ends, against the hub of plate ll, thus limiting the movement of the mass.

01 course, in addition to its application to devices for reducing the torsional vibrations of shafts, the principle of the invention may also be applied to any devices whatever which are intended to reduce vibrations and for instance to devices for absorbing the longitudinal vibrations of bodies moving along a rectilinear path.

- In a general manner, while I have, in the above description, disclosed what I deem to be practical and ei'flcient embodiments of the present inven-' tion, it-should be well understood that I do not wish to be limited thereto as there might be changes made in the arrangement, disposition,

and form of the parts without departing from the principle of the present invention as coinprehended within the scope of the accompanying claim.

What I claim is:

A device for reducing the vibrations of a moving part which comprises in combination two elements including a mass and a member connected to said moving part, a runway carried by one of the two aforesaid elements extending from one side of said last mentioned element to the other side thereof, two lugs carried by the other element, one disposed on each-side of said runway respectively, a runway carried by each of said lugs respectively on each side of the first mentioned runway and overlapping it, a cylindrical rolling body of less diameter than the least dimension oi. either runway adapted to cooperate with these three runways and extending longitudinally thereof, and two stops for preventing axial displacements of the rolling body, said stops being secured respectively to each of said lugs on either side of said rolling body RAOUL ROLAND RAYMOND BARAZIN. 

